From dddb0ac6a591a02a77c94164ae0db17dc5b2e5a1 Mon Sep 17 00:00:00 2001
From: Thomas Jungblut <tjungblu@redhat.com>
Date: Wed, 3 Aug 2022 18:27:26 +0200
Subject: [PATCH] UPSTREAM <carry>: etcdctl: allow move-leader to connect to
 multiple endpoints

Re-opening closed PR etcd-io#11775 which was originaly authored by benmoss.
Then again opened PR etcd-io#12757 which was authored by zerodayz.

The mustClientForCmd function is responsible for parsing environment
variables and flags into configuration data. A change was made in etcd-io#9382
to call Fatal if a flag is provided multiple times. This means that we
cannot call the mustClientForCmd function more than once,
since it will think that flags parsed the first time are now
being redefined and error out.

Some people have commented about this in etcd-io#8380 but I don't think
there's an open issue for it.

Signed-off-by: Thomas Jungblut <tjungblu@redhat.com>
---
 etcdctl/ctlv3/command/move_leader_command.go |  5 +--
 tests/e2e/ctl_v3_move_leader_test.go         | 33 ++++++++++++++++----
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/etcdctl/ctlv3/command/move_leader_command.go b/etcdctl/ctlv3/command/move_leader_command.go
index 098c897cd7a9..4e0b237e66f8 100644
--- a/etcdctl/ctlv3/command/move_leader_command.go
+++ b/etcdctl/ctlv3/command/move_leader_command.go
@@ -19,6 +19,7 @@ import (
 	"strconv"
 
 	"github.com/spf13/cobra"
+
 	"go.etcd.io/etcd/client/v3"
 	"go.etcd.io/etcd/pkg/v3/cobrautl"
 )
@@ -43,7 +44,8 @@ func transferLeadershipCommandFunc(cmd *cobra.Command, args []string) {
 		cobrautl.ExitWithError(cobrautl.ExitBadArgs, err)
 	}
 
-	c := mustClientFromCmd(cmd)
+	cfg := clientConfigFromCmd(cmd)
+	c := cfg.mustClient()
 	eps := c.Endpoints()
 	c.Close()
 
@@ -53,7 +55,6 @@ func transferLeadershipCommandFunc(cmd *cobra.Command, args []string) {
 	var leaderCli *clientv3.Client
 	var leaderID uint64
 	for _, ep := range eps {
-		cfg := clientConfigFromCmd(cmd)
 		cfg.endpoints = []string{ep}
 		cli := cfg.mustClient()
 		resp, serr := cli.Status(ctx, ep)
diff --git a/tests/e2e/ctl_v3_move_leader_test.go b/tests/e2e/ctl_v3_move_leader_test.go
index 05dc49939992..70bc50ac445b 100644
--- a/tests/e2e/ctl_v3_move_leader_test.go
+++ b/tests/e2e/ctl_v3_move_leader_test.go
@@ -27,15 +27,31 @@ import (
 	"go.etcd.io/etcd/client/v3"
 )
 
-func TestCtlV3MoveLeaderSecure(t *testing.T) {
-	testCtlV3MoveLeader(t, *newConfigTLS())
-}
+func TestCtlV3MoveLeaderScenarios(t *testing.T) {
+	securityParent := map[string]struct {
+		cfg etcdProcessClusterConfig
+	}{
+		"Secure":   {cfg: *newConfigTLS()},
+		"Insecure": {cfg: *newConfigNoTLS()},
+	}
 
-func TestCtlV3MoveLeaderInsecure(t *testing.T) {
-	testCtlV3MoveLeader(t, *newConfigNoTLS())
+	tests := map[string]struct {
+		env map[string]string
+	}{
+		"happy path": {env: map[string]string{}},
+		"with env":   {env: map[string]string{"ETCDCTL_ENDPOINTS": "something-else-is-set"}},
+	}
+
+	for testName, tc := range securityParent {
+		for subTestName, tx := range tests {
+			t.Run(testName+" "+subTestName, func(t *testing.T) {
+				testCtlV3MoveLeader(t, tc.cfg, tx.env)
+			})
+		}
+	}
 }
 
-func testCtlV3MoveLeader(t *testing.T, cfg etcdProcessClusterConfig) {
+func testCtlV3MoveLeader(t *testing.T, cfg etcdProcessClusterConfig, envVars map[string]string) {
 	BeforeTest(t)
 
 	epc := setupEtcdctlTest(t, &cfg, true)
@@ -94,6 +110,7 @@ func testCtlV3MoveLeader(t *testing.T, cfg etcdProcessClusterConfig) {
 		cfg:         *newConfigNoTLS(),
 		dialTimeout: 7 * time.Second,
 		epc:         epc,
+		envMap:      envVars,
 	}
 
 	tests := []struct {
@@ -108,6 +125,10 @@ func testCtlV3MoveLeader(t *testing.T, cfg etcdProcessClusterConfig) {
 			[]string{cx.epc.EndpointsV3()[leadIdx]},
 			fmt.Sprintf("Leadership transferred from %s to %s", types.ID(leaderID), types.ID(transferee)),
 		},
+		{ // request to all endpoints
+			cx.epc.EndpointsV3(),
+			fmt.Sprintf("Leadership transferred"),
+		},
 	}
 	for i, tc := range tests {
 		prefix := cx.prefixArgs(tc.eps)